Multi-sensor system for fluid monitoring with selective exposure of sensors

ABSTRACT

A multi-sensor apparatus for monitoring a fluid is described. The apparatus includes a plurality of sensors, wherein each sensor is configured to be exposed to a fluid, and includes at least one membrane that covers the plurality of sensors. A mechanical member or a heating element can be used to selectively expose a particular sensor to the fluid leaving another of the sensors unexposed to the fluid.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of copending U.S. patent applicationSer. No. 10/840,650 filed May 7, 2004 now U.S. Pat. No. 7,100,427 andentitled “Multi-Sensor System for Fluid Monitoring with SelectiveExposure of Sensors.” This application is also related to copending U.S.patent application Ser. Nos. 10/840,628, 10/840,639, and 10/840,649, allfiled May 7, 2004. The entire contents of each of the above-noted patentapplications is incorporated herein by reference

BACKGROUND

1. Field of the Disclosure

The disclosure relates generally to sensor systems and methods for fluidmonitoring. More particularly, the disclosure relates to sensor systemsand methods for wide distribution of sensors and on-line monitoring offluids (e.g., water).

2. Background Information

The quality and surety of drinking water is of ever increasingimportance throughout the world. Contaminants, such as toxins,biological agents, inorganic compounds and particulate matter that entera contiguous water distribution system either naturally, or arepurposely placed there as a terrorist act, have the capacity to diminishthe quality of the water to an unacceptable level, and each member ofthe population, whether human or other life form, is at risk of exposureto water of such substandard quality. Water can become contaminated atits source, whether that be from wells, rivers, reservoirs or treatmentplants, or can become contaminated once the water is introduced into acontiguous water distribution system. Regardless of its source or type,water quality degradation can have a significant detrimental healthaffect that can sometimes be seen quickly and often times is notrecognized or detected for years or even decades.

Measures have been taken for monitoring the quality of drinking waterincluding placing monitors at various points in the source water, inwater treatment plants, and/or at selected distribution points of waterdistribution pipe networks within a region of a water authority, forinstance. The selection, access to appropriate sites andacquisition/placement of water quality monitoring components and systemstend to be labor intensive and costly for a regional or multi-regionalwater authority to implement. This high cost and significant on-goingmaintenance requirement for remote monitoring systems has severelylimited the number of locations monitored and is the primary reason thatmost testing is performed on a low-volume basis by bringing “grabsamples” of water back to a laboratory for testing. Severalconsiderations are at issue: the density of testing (i.e., how manylocations in a reservoir or within a city should be monitored to protectthe population from exposure, e.g., each city block or within a 5-block,10-block or 20-block area); the frequency of testing (e.g., whethertaking a grab sample once a month for a given location is sufficient toprotect the population); and the time delay in receiving “actionable”data about contamination that may already be affecting tens of thousandsof people by virtue of the testing being done on a non-continuous basis.

Additionally, many water quality sensors create false positives, orfalse negatives, in determining substandard water conditions. Thesefalse positives can be expensive insofar as they require investigationand repair of a sensor node and could even result in the shut-down of awater distribution system section or, more commonly, an alert thatdisrupts a population's use of water. False negatives can be even morecostly if hazardous conditions are not timely detected.

Further, the need for sharing of water quality measurements,particularly in real time, is of ever increasing importance. Not only doregional water authorities need real time measures of water quality toimprove system performance, multiregional (e.g., county, province, stateor national) water authorities desire original data whether in the formof raw data or analyzed results of the water quality in a particularwater distribution region. This information can be used to assurecompliance with water quality standards, for instance. This informationis generally provided by the regional water authorities, which may nothave sufficient incentives to provide completely candid reports. Also,in these uncertain times, real time awareness of possible or actualsabotage can be of critical importance, if only to provide assurance tothe general population that the water supply is safe.

Thus, there is a need for improvements in sensing whether a municipal,industrial or even home water purification/treatment system is operatingproperly and providing water of a certain quality. This can beparticularly important when a municipality places water treatmentequipment in remote locations to selectively or more cost effectivelytreat water instead of treating the entire bulk water at themunicipality.

Finally, there is a need to confirm the purity and surety of water soldas pure from a commercial water treatment system in order to verifymanufacturers claims of providing pure water.

SUMMARY OF DISCLOSURE

Various embodiments of the present disclosure address these as well asother concerns raised by the state of the art.

For instance, the present invention can include a system for monitoringa fluid that includes monitoring, identifying, confirming and thenreporting a detection event. Several embodiments of monitoring means formonitoring a fluid and generating a variable based on the monitoring,and for generating a preliminary identifier if the variable isindicative of a detection condition, are disclosed. Similarly, severalembodiments of confirming means for testing the fluid and fordetermining whether the detection condition has occurred based on newdata, are also disclosed. Additionally, several embodiments of reportingmeans for reporting the detection condition to a remote communicationdevice, if the confirming means determines that the detection conditionhas occurred, are disclosed.

More specifically, embodiments of the present invention can be in theform of a system for monitoring a fluid, which includes a first sensorconfigured to be exposed to a fluid and a second sensor configured to beexposed to the same fluid sample. Such a system may also include aprocessing unit coupled to the first sensor and the second sensor, theat least one processing unit being configured to (1) operate inconjunction with the first sensor to monitor the fluid, (2) generate avariable based on its monitoring, (3) generate a preliminary identifierif the variable is indicative of a detection condition, and (4) operatein conjunction with the second sensor to determine whether the detectioncondition has occurred based on new data. A communication unit can beconfigured to report the detection condition to a remote communicationdevice if the processing unit confirms that the detection condition hasoccurred. The method being carried out by these means is also disclosed.

In another example, a system for monitoring a fluid can include a fluidtreatment device; a first sensor configured to be exposed topre-treatment fluid that enters the fluid treatment device; and a secondsensor configured to be exposed to post-treatment fluid. The fluidtreatment device can comprise for instance a filter housing, a filter, awater-softening device, a distillation device, a reverse-osmosisfiltration device, or any combination thereof, as an example.

In another example, a multi-sensor apparatus for monitoring a fluid isalso disclosed. The multi-sensor apparatus can include, for instance, asubstrate; a plurality of sensors attached to the substrate, each sensorconfigured to be exposed to a fluid; and one of several means forselectively exposing a particular sensor of the plurality of sensors tothe fluid, and their equivalents. The exposing means can include, forinstance, a membrane attached to a surface of the substrate, themembrane covering the plurality of sensors; and a plurality of heatingelements attached to the membrane, a given heating element beingpositioned proximate to a given sensor, wherein each heating element isselectively operable to generate an opening in the membrane, therebyallowing a particular sensor positioned proximate to the opening to beexposed to the fluid. Alternatively or additionally, the exposing meanscan include a housing member in which the substrate is disposed, thehousing member having an aperture in a wall thereof configured to allowa sensor to be exposed to a fluid; a seal arranged adjacent to theaperture and positioned between a surface of the substrate and a surfaceof the housing, thereby sealing the substrate against the housing; andan actuator for moving the substrate to selectively locate a individualsensor or group of sensors to a region of the aperture such that theindividual sensor or sensor group is exposed to the fluid. In stillanother embodiment, the exposing means can be in the form of at leastone cover membrane attached to a surface of the substrate, the at leastone cover membrane covering the plurality of sensors; and a mechanicalmember for selectively displacing the at least one cover membrane in aregion proximate to an individual sensor or sensor group to allow thesensor or sensor group to be exposed to a fluid; and an actuator forproviding relative motion between the substrate and the mechanicalmember to allow the mechanical member to selectively displace the atleast one cover membrane.

Sensor units in accordance with these aspects of the disclosure canmonitor, identify, confirm and report detection events on a continuousor intermittent (e.g., periodic) basis to thereby reduce the incidenceof either or both of false positives and false negatives.

Sensor systems in accordance with these aspects of the disclosure canprovide a wide and potentially random distribution of sensor sitesthroughout a water distribution system at identifiable locations,potentially at final fluid output points (e.g., water facets) at the enduser locations, establishing a potentially larger panel of monitoringsites than might otherwise be achievable within a similar level ofexpense. This is particularly true in circumstances where end usersvoluntarily pay for and install sensors units, providing advantages forthemselves at the same time advantages are made available to watermonitoring entities and the general public. The potential for largepanels of distributed sensor sites increases the ability for waterauthorities to detect, trace and/or isolate sources of problemsaffecting water quality within a water quality monitoring system.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will now be explained with reference to exemplaryembodiments illustrated in the accompanying drawings to which theinvention is not necessarily limited. Various advantages and otherattributes of the invention will be identified or become apparent withrespect to various specific embodiments, but not all embodiments withinthe scope of the present invention will necessarily include or haveidentified advantages or attributes. The scope of the invention shouldbe determined based on recitations contained in the claims, andequivalents thereof, rather than reliance on advantages and attributesnot positively recited in the claims. Further, although the term“invention” has been used in the singular, it should be recognized thatmore than one independent and/or distinct invention may be presented inthe disclosure and claims.

FIG. 1A is a block diagram of an exemplary embodiment of a sensor unitin accordance with an embodiment of the present disclosure.

FIG. 1B is a block diagram of another exemplary embodiment of a sensorunit in accordance with another embodiment of the present disclosure.

FIG. 1C is an illustration of an exemplary embodiment of a sensor unit.

FIG. 1D is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1E is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1F is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1G is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1H is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1I is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1J is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1K is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1L is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1M is an illustration of another exemplary embodiment of a sensorunit.

FIG. 1N is an illustration of another exemplary embodiment of a sensorunit.

FIG. 2 is a block diagram of an exemplary sensor unit supply chain inaccordance with aspects of the present disclosure.

FIG. 3 is a block diagram of an exemplary data collection network, datadistribution network and data analysis network in accordance withaspects of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

For purposes of this document, the following should be understood. Theterm “water quality” generally relates to measures of various aspects ofwater or other fluids and fluids that tend to indicate the usefulness ofor danger posed by a fluid including but not limited to the measure ofvarious chemicals, chemical profiles, presence of biological agentsand/or life forms, toxins, other organic and inorganic contaminants, andparticulates, etc. For instance, although water distribution systems area focus of several embodiments of the present invention, it is alsopossible that aspects of the present invention can be applied to monitorany fluid (gas or liquid) including those present in a distributionsystem, reservoir or feed source in need of monitoring. The term“confirm” should be understood to mean that additional evidence orsupport by another indication has been determined based on additionalinformation, which can be of the same or a distinct type relative to thedata leading to the original indication. “Distribution system” includesany system of fluid distribution (including air distribution systemssuch as, for example, air ducts), which in the case of waterdistribution, currently commonly manifest themselves as contiguoussystems of pipes and/or systems of reservoirs, channels, pipes andtreatment plants, but also can include less typical distributionchannels such as container water, well water within a watershed or awater table, and even large bodies of water, oceans, rivers, streamsand/or tributaries, or virtually anything wherein a fluid can flow fromone point in the system to another, such as movement of water from onelayer to another layer within a single body of water, a hallmark ofwhich is the ability to identify the location of and communicate withsensor units within the water distribution system. Also, the phrase“same sample of fluid”, “the fluid” and the like should be understood tomean any quantity of the fluid wherein the same or similar conditionsare likely to exist. For example, for broad measures such as pH in abody of non-static water, all of a large pool or reservoir might be thesame sample, whereas for detecting trace elements or alarmingconditions, a water sample might mean only a few milliliters. The term“measuring” is not limited to embodiments wherein a numeric value orother analog or digital value is generated, but rather includes sensorsand sensor elements that simply output a defined signal when a threshold(either an upper or a lower or both) is crossed. A sensor unit includesone or more sensors, sensor elements and/or sensor groups within ahousing or located at a site, and includes processing and/orcommunication components. A sensor is a device designed to sense aparameter or parameters of a fluid and outputs a signal, typically to aprocessor. A sensing element is an element that forms part of a sensorand actually performs the measurement. The sensing elements of a sensorcan be associated or coordinated in some fashion to perform monitoringand detection functions as a group, perhaps to determine a chemicalprofile of a sample. A sensor component is a generic term meaning anyone of a sensor unit, sensor, or sensing element. A processing unit is ageneric term meaning one or more processing units programmed at asoftware, firmware or hardware level, including, for example, ASIC(application specific integrated circuit). A processing unit can bemultiplexed to multiple sensors or dedicated to a single sensor.

Sensors

Exemplary sensors can be selected to include any form of fluid measuringsensors; such as water quality measuring sensing elements includingsensing elements for determining water temperature, water pressure, thepresence or absence of any number of specific chemicals, chemicalprofiles and/or classes of chemicals such as for example and withoutlimitation free chlorine (Cl⁻), hypochlorous acid (HOCl) andhypochlorite ions (OCl⁻), ion concentration, pH, carbon dioxide (CO₂),water hardness (e.g., Ca²⁺), carbonate (CO₃ ²⁻), monochloromine (NH₂Cl),dichloramine (NHCl₂), trichloramine (NCl₃), ammonium, nitrite, nitrate,fluoride, and/or chemical profiles, as well as determining water purity,clarity, color and/or virtually any other measurable or detectableparameter of interest with respect to water or any other fluid. Somesuch sensors are described in copending U.S. patent application Ser. No.10/657,760 (“Method and Apparatus for Quantitative Analysis”), theentire disclosure of which is incorporated herein by reference. Suchsensors can be used to monitor not only liquids, but also, withappropriate calibration, gases (e.g., air) as well. Such sensors caninclude one or more of, for example, electrodes and ion-selectivemembranes acting as ion-selective electrodes (ISEs), amperometric andpotentiometric sensing elements that may or may not have electrodecoatings on the electrode surfaces, conductivity sensing elements,temperature sensing elements, oxidation-reduction potential sensingelements, reference electrodes, oxygen sensing elements, immunosensors,DNA probes (e.g., hybridization assays with oligonucleotides) comprisingappropriate coatings on electrode surfaces and a wide variety of opticalsensors, to name a few. Other suitable sensor devices include thosedisclosed in U.S. Pat. No. 4,743,954 (“Integrated Circuit for aChemical-Selective Sensor with Voltage Output”) and U.S. Pat. No.5,102,526 (“Solid State Ion Sensor with Silicone Membrane”), thedisclosures of which are incorporated herein by reference.

Sensors for use in systems disclosed herein, such as those disclosed incopending U.S. patent application Ser. No. 10/657,760, U.S. Pat. Nos.4,743,954, and 5,102,526, for example, can be fabricated using knownlithographic, dispensation and/or screen printing techniques (e.g.,conventional microelectronics processing techniques). Such techniquescan provide sensors having sensing elements with micro-sized featuresintegrated at the chip level, and can be integrated with low-costelectronics, such as ASICs (applications specific integrated circuits).Such sensors and electronics can be manufactured at low cost, therebyenabling wide distribution of such sensors to various entities,including private entities.

Exemplary sensors can be fabricated on silicon substrates or can befabricated on other types of substrates such as, for example, ceramic,glass, SiO₂, or plastic substrates, using conventional processingtechniques. Exemplary sensors can also be fabricated using combinationsof such substrates situated proximate to one another. For example, asilicon substrate having some sensor components (e.g., sensing elements)can be mounted on a ceramic, SiO₂, glass, plastic or other type ofsubstrate having other sensor components (e.g., other sensing elementsand/or one or more reference electrodes). Conventional electronicsprocessing techniques can be used to fabricate and interconnect suchcomposite devices.

Also, a variety of other sensors, whether commercially available or notincluding those not yet developed, could be used within the systemdisclosed herein. While novel sensor units comprising various sensorsare disclosed herein, other novel aspects of the present disclosureremain novel regardless of the form of sensor units. With regard tomonitoring of gases such as air, any suitable sensor for detecting atarget species can be used, such as, for example, electrochemical gassensors including electrochemical sensors for detecting hydrogen cyanideas disclosed in U.S. Pat. No. 6,074,539, the entire contents of whichare incorporated herein by reference.

Exemplary Monitor, Confirm and Report Systems

In one embodiment of the present disclosure shown in FIG. 1A, a systemfor monitoring water quality (or quality of any fluid) (330 in FIG. 3)can include a sensor unit 110 that includes a first sensor 111A and anassociated processing unit 112A acting as a monitoring means formonitoring a fluid and generating a variable based on the content of afluid. This processing unit 112A can be housed in a module 112 alongwith a communication unit 112B. This first sensor 111A either upon thedetection of a quality in the fluid or by the measured or calculatedvariable associated with the fluid crossing a threshold, for instance,can generate a preliminary identifier if the variable is indicative of adetection condition. For instance, if the pH level (as the variable) orother water quality parameter rises too high or low, or the waterpressure as measured by an incorporated pressure monitor drops below athreshold for instance, a preliminary identifier (e.g., a flag or asignal) is generated in this exemplary system. This preliminaryidentifier can trigger a second sensor 111B to begin measuring the samevariable or a different variable, or to output a continuously measuredresult. The processing unit 112A can comprise a single processing unitor multiple processing units.

Alternatively, the second sensor 111B can be run in tandem with thefirst sensor 111A for testing the same sample of fluid a second timeeither using the same test or a different test that also is indicativeof a detection condition. The results of the measures or tests areoutput from the processor as a confirmed result when they agree. Thesecond sensor 111B and the processing unit 112A act as a confirmingmeans for the first sensor or monitoring means 111A.

Alternatively, the second sensor 111B can be in the form of the firstsensor 111A that is recalibrated for the second test.

Upon a positive result from the first sensor 111A in conjunction withthe processing unit 112A (acting together as monitoring means) and apositive result from the second sensor 111B (or more sensors) inconjunction with the processing unit 112A (together acting as confirmingmeans), the detection condition is communicated or reported by acommunication unit 112B (acting as reporting means) to a remotecommunication device and/or a local indicator (e.g., a light or otherform of alert on the sensor unit housing). Information regarding fluidmeasurement results can also be displayed on an optional display (e.g.,located on the sensor unit housing). This form of sensor unit 110thereby eliminates many false positives insofar as before a detectioncondition is reported, it is confirmed.

Also, more than one sensor can act as either the first and/or secondsensor 111A, 111B to provide redundancy of tests or measures. In thisway, if one sensor fails, another sensor acting in the same capacityacts as a back-up to reduce the chances of a false negative. Whetherthrough detection of false positives or false negatives, or other means,a defective sensor or other sensor component can be deactivated by aprocessing means, for instance by simply not supplying power or notprocessing output from the defective sensor component.

As illustrated in the exemplary embodiment of FIG. 1A, the sensors in asensor unit 110 can take the form of a first sensor 111A and a secondsensor 111B and even more sensors 111C as circumstances warrant. Suchsensors can collectively be referred to as a sensor group, which canalso simply be referred to as sensor 111. Sensors of a sensor group maybe physically configured together as a unit, but this is not necessary.For instance, the third sensor 111C can be provided to serve as part ofthe confirming means, thereby allowing the processing unit 112A todetermine whether the detection condition has occurred based on amajority voting approach using data from the first sensor 111A, thesecond sensor 111B and the third sensor 111C, e.g., each sensor111A-111B gets one vote or a weighted vote perhaps in the form of ananalog or digital signal, and the condition indicated by a majority ofsuch votes is reported to a remote communication device or localindicator. The third sensor 111C (or any number of additional sensors)can act as back-up sensors, or be used to further reduce false positivesand/or false negatives using a majority voting technique. Such sensorscan include, for example, electrodes and ion-selective membranes actingas ion-selective electrodes (ISEs), amperometric and potentiometricsensing elements that may or may not have electrode coatings on theelectrode surfaces, conductivity sensing elements, temperature sensingelements, oxidation-reduction potential sensing elements, oxygen sensingelements, immunosensors, DNA probes (e.g., hybridization assays witholigonucleotides) comprising appropriate coatings on electrode surfacesand a wide variety of optical sensors, to name a few.

The sensors 111A-111C can each be made up of a single sensor element113A, a plurality of sensor elements 113A-113C, perhaps for redundancy,or one or more sensor groups, as shown in FIG. 1B. The sensor elements113A-113C can be of the same type or of different types to measure, forexample, the same parameters for sake of redundancy and greateraccuracy, or measure different aspects of a chemical or biologicalprofile or signature. The first sensor 111A and/or the second sensor111B can, for instance, can respectively comprise a sensing element 113Acapable of measuring an ion content and a sensing element capable ofmeasuring a chlorine content. More generally, the sensors 111A-111C cancomprise at least one of an ion-selective sensing element, anamperometric sensing element, a potentiometric sensing element, aconductivity sensing element, a temperature sensing element, anoxidation-reduction potential sensing element, a chlorine sensingelement, an oxygen sensing element, an immunosensor, a DNA probe and anoptical sensor. The sensors 111A-111C can be provided on distinctsubstrates, or be provided on the same substrate 116, as shown in FIG.1C.

The processing unit 112A and the communications unit 112B act as thereporting means for reporting a confirmed event based on processed datafrom the first and second sensors 111A, 111B, or any number of aplurality of sensors 111 in a sensor unit 110.

In one exemplary embodiment, each of the plurality of sensors 111A-11Cis of the same type for monitoring the same parameters or profile of thefluid. In this way, if a first sensor 111A indicates false positives,the second sensor 111B would act to confirm or not confirm any detectionevent thereby reducing the number of reported false positives.Alternatively, the first sensor 111A may be of a more robust nature butperhaps lower sensitivity or have a broader range of detectableconditions, whereas the second sensor 111B might be more sensitive or ofa limited detection range or of a special type to detect a specificsubstance (one-shot sensors) and under these circumstances might beinvoked, for instance, only when the first sensor 111A generates apreliminary identifier indicative of a detection condition. For example,where the first sensor 111A has an array of sensing element of the typesnoted above, and generated a profile reading suggestive of cyanide, forexample, a one-shot sensor that can specifically detect cyanide ordetect smaller amounts of cyanide, can be activated or exposed. Thesecond sensor 111B, being more sensitive or more be capable of moreaccurately identifying a given detection condition, would then be betterable to confirm the existence of a detection event with greatercertainty.

The second sensor 111B could have at least one characteristic such asgreater sensitivity, more specific sensitivity, or be able to detectsecondary traits of a suspected substance indicated by the preliminaryidentifier. In the later case there might be a plurality of secondsensors 111B each associated with a given, more specific test or measureof the quality of the fluid, and activated as a group or individuallybased on the information contained in the preliminary identifier. Thesecond sensor 111B could, however, be the same type of sensor as thefirst sensor 111A in certain embodiments.

Further, the second sensor 111B can be coupled to a mechanism to changethe fluid or its environment prior to detection by the confirmationsensor. For instance, a single sensor 111A can be utilized and, upongenerating a preliminary identifier, a recalibration solution can beinjected by pumps, valves, microfluidics or other means, onto thesensor, wherein the recalibration solution has a known, constantparameter measurable by the sensor 111A to recalibrate the sensor 111Afor a subsequent measurement. Alternatively, a reagent can be introducedinto the fluid, the reagent being specific to the detection condition tochange the nature of the fluid in a controlled fashion to assist inidentifying the constituents of the fluid that is causing the detectioncondition. Enough recalibration fluid or reagent could be supplied tolast the expected life of the sensor 111A, or be in the form of areplenishable supply.

For instance, as illustrated in FIG. 1C, a fluid control device such asa valve 15A is located on the input side of a senor unit 110. The valve115A could then toggle between allowing fluid from the distributionsystem into the sensor unit 110 and allowing a calibration fluid intothe sensor unit 110. On the output side of the sensor unit 110, asimilar fluid control device such as a valve 115B can be used to removethe calibration fluid as waste, if introducing it into the monitoredfluid raises potential concerns or the output fluid control device canbe omitted if allowing the fluid in the sensor unit 110 to rejoin thefluid in the distribution system does not raise concerns.

The single sensor 111A may be thereby recalibrated by exposure torecalibration agent or the like, but alternatively can be simplyelectrically recalibrated by normalizing its response based onbackground conditions.

As perhaps easier to understand with respect to the fluid monitoringsystem of FIG. 3, one sensor can be used to calibrate another sensor.More specifically, in a network situation, a new sensor placed into thesystem could be used to calibrate older sensors that might have beensubject to calibration drift over time. The old and new sensors woulddetect the same fluid either in the fluid distribution system or asreagents or calibration solutions, and the new sensor readings would beused to adjust or calibrate the older sensor. The sensors ought to beneighboring, or relatively remote, as long as the fluid being used issubstantially the same in relevant ways, e.g., has the same pH, is takenfrom a small sample or a sample likely to have the same or uniformcharacteristics. The recalibration sensor merely has to be measuring aparameter that is similar enough to the sensor to be recalibrated tomake the recalibration effective.

The recalibration sensor and the sensor to be recalibrated cancommunicate through any suitable means for reporting, such as described,for example, in the different embodiment disclosed herein, to arecalibration circuit. The recalibration circuit may be in the form ofprogramming in a computer at a centralized location, such as the smartnodes 332 or centralized data collection points 333 as shown in FIG. 3,or a circuit or ASIC processor units in a module 112 such as disclosedin the embodiments of FIGS. 1 and 2. The recalibration circuit wouldhave received, either through human input or by any suitable automaticmeans including the registration of a new or replacement sensor, anindication that the newer sensor, generally, would be the recalibrationsensor, assuming that calibration drift of older sensors is a problembeing addressed.

Further, once one sensor is recalibrated it can be used to calibrate thenext in a network, for instance, to create a domino effect forrecalibration of sensors measuring fluid having a relatively uniformmeasurement characteristic. For instance, an individual pipe withmultiple sensors spaced along it can sequentially recalibrate the nextsensor at a rate equal to fluid flow through the pipe.

The sensors 111A-111C can be any combination of the above and there maybe a multiplicity of individual sensors, some or all of which maycomprise a plurality of sensing elements. For instance, a sensor (e.g.,sensor 111B in FIG. 1B) can have a plurality of sensing elements113A-113C to detect multiple parameters within the fluid. Only threesensing elements 113A-113C are illustrated in FIG. 1B, but more thanthree could be employed. In this way, a sensor 111A can be used toidentify chemical signatures or profiles within a fluid (e.g., potablewater).

A sensor 111A, such as shown schematically in the example of FIG. 1E canbe made up of individual sensing elements 113A-113F. These sensingelements 113A-113F can be designed to identify different ranges ofparameters within a fluid, specific chemicals or substances (e.g.,compounds, contaminants) or identify different possible water qualitymeasures, as tailored to the specific expected needs of the waterquality monitoring system. Together, such sensing elements 113A-113F canprovide a chemical profile of a fluid or can provide data indicative offingerprints of particular substances (e.g., compounds, contaminants) orclasses of substances (e.g., compounds, contaminants). The sensingelements 113A-113F may be mounted on a recessed surface, as shown inFIGS. 1D and 1E or they may be mounted on a non-recessed surface. Thesensing elements 113 shown in the recesses 116A of FIG. 1D do notnecessarily form a profile on the surface, as shown for emphasis in FIG.1D, but may instead be co-planar with the surface. Electricalconnections are mounted or formed on a substrate 116 in any or manyknown ways to connect the sensing elements 113A-113F to a processingunit 112A.

Whenever a plurality of sensor components (e.g., 111A-111C, 113A-113F)are incorporated into a sensor unit 110, they may each have a separateprocessing unit 112A and/or communication unit 112B, or may share commonsuch components via a multiplexer or the like to reduce costs andcommunication overhead (bandwidth, power consumption, etc.). Forinstance, ASIC (applications specific integrated circuits) can beutilized to develop sensor units 110 of efficient design. These ASICscan be on a common substrate, or multiple substrates coupled togetherthrough electrical connections.

One or more sensors 111 can provide indications of event conditions on anumber of bases, including one or more out-of-range events wheremeasured parameters or profiles within a fluid exceed or deviate from aparticular range and/or threshold either preprogrammed or downloadedinto the sensor unit 110. The sensor units 110 can also providedetection of water profile parameters for comparison against waterprofile parameters either downloaded into the sensor units 110 or atsmart nodes 332 or centralized data collection points 333, as explainedin greater details with reference to FIG. 3, below. The detection ofchemical fingerprints, signatures or profiles would be coupled to adatabase of potential chemical profiles for positive identification ofeven complex contaminants including biological agents and chemicaltoxins, for example. In this regard, such a database of potentialchemical profiles can be stored locally (e.g., on-chip) in a memoryinterfaced to the processing unit 112A, or can be stored at one moreremote locations for on-line access by the processing unit 112A andcommunication unit 112B. In either case, the database of potentialchemical profiles can be updatable, and in the case of the local memory,the database of potential chemical profiles can be downloadedintermittently into the local memory. Suitable pattern recognitiontechniques can be used to compare data generated by the sensor unit(s)110 with the database of potential chemical profiles to generate apotential identification event if there is a potential match with one ormore stored chemical profiles.

Physical events, such as a breakage of a pipe might be detected througha pattern of sensor units 110 reporting readings that deviate fromhistoric norms, for example, reduced water pressure compared to historicnorms, thereby identifying the exact location or proximate location ofthe breakage. Also, temperature sensors could be utilized to normalizeand scale temperature dependent detection mechanisms but also may beutilized to determine when water distribution systems are at risk ofbreakage through freezing temperatures.

The sensor unit 110 includes processing and communication units 112A and112B. The communication capability of the sensor units 110 can includehardwired communication circuits wherein the unit is literallyphysically connected by wires to other communications devices orcommunication systems such as telephone lines, satellite or wirelesscommunication devices, etc. The communication unit 112B may also imposeinformation on a carrier for existing power lines within the building oreven the power grid of a region. The imposed information signals wouldthen be picked up by local communications devices for long-rangecommunication over telephone lines, private or public networks, cellularcommunication networks, SMS (short message service) networks,satellites, etc. Additionally or alternatively, the communication unit112B of an individual sensor unit 110 can include short-range wirelesscapabilities for communication with local alert and/or long-rangecommunication devices such as telephones, private or public networks,cellular communication networks or satellite devices that may preexistor be installed for communication with a sensor unit 110. Suchshort-range wireless devices include communication devices utilizingunregulated spectrums using existing protocols such as Bluetooth.Alternatively, wireless LAN protocols such as dictated by IEEE Standard802.11(b) or 802.11(g) could be used, as could long-range wirelessdevices for transmission to relatively distant stations such as atreceivers located at the headquarters of regional water authorities.Other alternatives include communication devices 112B which utilize apreexisting cellular network or wireless networks such as those used byalarm systems. The manner of communication might be dictated by externalfactors including availability, cost, robustness, efficiency, etc.

A network of sensor units 110 as described herein can be configured tocommunicate with a central communication device, e.g., a server, and/orsensor unit 110 can communicate with each other as a distributednetwork, using communication components known in the art. In this way,for example, a first sensor 111A can generate a preliminary identifierif it measures a water quality variable indicative of a detection event(e.g., low chlorine in a potable water system) and can trigger aneighboring second sensor 111B via the distributed network to make aconfirmation measurement.

Finally, or in addition to, the communication unit 112B can includeon-site alerts such as optical (indicator lights), audible alerts (e.g.,alarm sounds), tactile (e.g., vibration of the unit) or can beinterfaced to an appropriate control valve for simply shutting off thesupply of fluid upon the detection of emergency events, for instance.

Packaging and Location

The sensor units 110 can be packaged and located in a variety of ways.For instance, they can be placed at the shut off valve located at theintroduction of water supply into a house, business, industrial site orgovernment site, for instance. Alternatively, they can be placed at eachindividual faucet or selected faucets where it is likely that the enduser 23 might drink water or otherwise consume or cause fluids to beconsumed. For instance, water filtration devices adaptable forattachment at the end of a faucet can be adapted to incorporate a sensorunit 110 and include both communication devices that communication withdistant locations as well as integrally housed alerts either of anoptical, audible or tactile nature. Also, sensor units 110 can belocated at any desired points in a municipal water distribution system.

Filter Package Monitors

One exemplary embodiment of the present invention combines a waterfilter and/or water treatment device with one or more sensor units 110.As illustrated in FIG. 1F, a system for filtering and monitoring a fluidincludes a filter unit 114. The filter unit 114 includes a filterhousing 114A for holding a filter 114B. A first, intake sensor 114C isconfigured to be exposed to fluid that enters the filter unit 114(pre-filtering fluid, or more generally, pre-treating fluid). A second,output sensor (post-filtering fluid) 114D is configured to be exposed tofluid filtered by the filter 114B (post-filtering fluid, or moregenerally, post-treating fluid). The first, intake sensor 114C caninclude a plurality of sensors 111A, 111B, 111C, etc., each of which canhave one or more sensing elements 113A, 113B, 113C, etc., as can thesecond, output sensor 114D, such as described above. The individualsensors 111A, 111B, 111C, etc., can act as the monitoring and confirmingmeans for each sensor 114C, 114D, depending on how they are connectedand used by a processor 112A, or the intake or output sensing 114C, 114Dcan act as respective monitoring and confirming means (the roles beinginterchangeable) for fluid quality measures that are not effected by thefilter 114B.

For instance, the first, intake sensor 114C can include an ion-selectivesensing element capable of measuring an ion content and a chlorinesensing element capable of measuring a chlorine content. Likewise, thesecond, output sensor 114D can include an ion-selective sensing elementcapable of measuring an ion content and a chlorine sensing elementcapable of measuring a chlorine content. Moreover, each sensor 114C and114D can comprise additional sensing elements, e.g., electricalconductivity and/or other sensing elements, capable of generating asuite of measurements that can provide particular measurements, whichcan be combined to generate a fluid-quality profile. For example, thesensors 114C and 114C can comprise at least one of an ion-selectivesensing element, an amperometric sensing element, a potentiometricsensing element, a conductivity sensing element, a temperature sensingelement, an oxidation-reduction potential sensing element, a chlorinesensing element, an oxygen sensing element, an immunosensor, a DNA probeand an optical sensor.

The filter unit 114 can further include a processing unit 112A coupledto the first and second sensor units 114C, 114D, the processing unit112A being configured to compare measurement data generated by the firstand second sensor units 114C, 114D.

The filter unit 114 can also include a communication unit 112B, eitheras part of or separate from the processing unit 112A, but coupled to theprocessing unit 112A. The communication unit 112B can be configured tocommunicate measurement results (e.g., raw and/or processed data)generated by the processing unit 112A to a remote communication devicein the exemplary embodiment of FIG. 1C. It should be noted too that theprocessing unit 112A can be in the form of a first processing unit and asecond processing unit, wherein the first processing unit is arrangedwith and coupled to the first sensor 114C, and wherein the secondprocessing unit is arranged with and coupled to the second sensor 114D.The first and second processing units can be coupled together to achievethe desired measurement and comparison functions. Also, as with otherembodiments described herein, sensor units 110 (whether or not packagedwith a filter) can be monitored by a water treatment provider for thepurpose of guaranteeing or certifying the quality of filtered and/orotherwise treated water. For example, a private water treatment companyor a municipality can provide on-line monitoring of waterfiltration/treatment equipment at a delivery point (e.g., a home orbusiness), and as part of its service, can guarantee or certify thequality of filtered and/or otherwise treated water. The waterfiltration/treatment equipment can be provided and/or installed by themonitoring entity or by a different entity. Further, one or more sensorsplaced at the water intake of a filter/treatment unit can be used topredict how long a treatment element (e.g., filter element) is expectedto last based on loading capacity of that element and the amount ofcontaminants present in the intake water as measured by the sensor(s),and this information can be communicated on-line to the water treatmentprovider by any suitable method as disclosed herein.

As for packaging, the first and second sensor 114C and 114D can beattached to the filter housing 114A, but the filter 114B that filtersthe fluid can be replaceable without necessarily replacing the first andsecond sensors 114C, 114D depending on the particular embodiment. Thesensors 114C, 114D can be designed to last the life of the filter unit114, or be separately replaceable or replaceable with the filter 114B.In the latter case, it might be expedient to have the first and secondsensor units 114C, 114D attached to or embedded in the filter 114B, suchas shown in the exemplary filter unit 114′ illustrated in FIG. 1G. Inthis regard, an appropriate interface, such as a waterproof plug, can beprovided to couple the sensors 114C, 114D to the processing unit 112A.

In this way, the processing unit 112A is configured to generate anidentifier to indicate a replacement condition for a filter 114B to beplaced in the filter housing 114A based upon the comparison of themeasurement data from the first and second sensor units 114C and 114D.An indicator 114E (e.g., a simple light, with or without a label, or anaudible indicator) that indicates the replacement condition for thefilter might be included as attached to or part of the filter housing114A for instance, and/or the communication unit 112B might communicatethe replacement condition to a remote communication device. Optionally,a display 114G can be provided for displaying information such as waterquality measurements, date of last filter change, and/or remainingfilter life (based on known loading specifications of the filter 114Band measurement data obtained by the sensors 114C and 114D).

In still other variations, a third sensor unit 114F configured to beexposed to the fluid that enters the filter housing 114A can beemployed, wherein the third sensor 114F is coupled to the processingunit 112A. The processing unit 112A would be in this embodimentconfigured to operate in conjunction with the first sensor 114C tomonitor the fluid, generate a variable based on said monitoring,generate a preliminary identifier if the variable is indicative of adetection condition, and operate in conjunction with the third sensor114F to determine whether the detection condition has occurred based onnew data. As explained above, this monitor and confirm function can becarried out with sensors 111 configured within the same sensor unit 110,but the raw data can be communicated to a central location for thisprocessing, and the central location can then be instructed whether tocarry out the confirmation function.

As with other embodiments, this embodiment can include a communicationunit 112B configured to report the detection condition to a remotecommunication device if the processing unit 112A confirms that thedetection condition has occurred, and/or provide raw data and/orprocessed data to a remote communication device. Additionally oralternatively, the processing unit 112 might be configured to generate asensor alert identifier if the third sensor unit 114F provides ameasurement reading that differs by a predetermined amount from acontemporaneous measurement reading of a same type provided by the firstsensor unit 114C. This configuration might serve as an indication thatthe first sensor unit 114C may be faulty. The first sensor unit 114Ccould then be deactivated by the processing unit 112A.

As with other embodiments disclosed herein the first and second sensorunits 114C and 114D can include an ion-selective sensing element capableof measuring an ion content, a chlorine sensing element capable ofmeasuring a chlorine content and a conductivity sensing element capableof measuring electrical conductivity, for example. More generally, thesensors 114C and 114C can comprise at least one of an ion-selectivesensing element, an amperometric sensing element, a potentiometricsensing element, a conductivity sensing element, a temperature sensingelement, an oxidation-reduction potential sensing element, a chlorinesensing element, an oxygen sensing element, an immunosensor, a DNA probeand an optical sensor.

As also with other embodiments of the present invention, the module 112can be attached to the filter housing 114A as shown in FIG. 1G, or canbe configured as a stand-alone unit coupled to the sensors 114C, 114Dvia electrical (wired or wireless) connections, wherein the module 112could be mounted on a wall or plugged into a power outlet. Of course,the processing unit 112A can be in the form of a first processing unitconnected to the first sensor unit 114C, and a second processing unitconnected to a second sensor unit 114D. The first and second processingunits can thereby be configured to compare measurement data generated bythe first and second sensor units 114C and 114D.

The processing unit 112A, however physically configured, could beconfigured to communicate with a communication unit 112B and to instructthe communication unit 112B to report the detection condition to anothercommunication unit if the processing unit 112 confirms that thedetection condition has occurred and/or raw data, in this exemplaryembodiment.

Although the examples described above have referred to a filter unit114, the filter unit 114 could be any suitable fluid-treatment devicesuch as, for example, a water-softening device, a distillation device,or a reverse-osmosis or membrane filtration device, media filtrationdevice, or any combination thereof, including or filter housing and/or afilter.

Multiple Sensors with Selective Exposure

With reference to FIG. 1D, a multi-sensor apparatus for monitoring afluid can include a substrate 116 and a plurality of sensors, each ofwhich can include one or more than one sensing element attached to orformed in or on the substrate 116. In FIGS. 1D, 1E and 1I individualsensors are identified by reference numeral 111, and individual sensingelements are identified by reference numeral 113, for brevity. Eachsensor 111 is configured to be exposed to a fluid. Also, a mechanism(discussed below) for selectively exposing individual sensors of theplurality of sensors 111 to the fluid is provided in this embodiment. Aswith other embodiments at least one of the sensors 111 can include aplurality of sensing elements 113 and at least one of the sensors 111can included both an ion-selective sensing element capable of measuringan ion content and a chlorine sensing element capable of measuring achlorine content, for instance. More generally, at least one of thesensors 111 can comprise at least one of an ion-selective sensingelement, an amperometric sensing element, a potentiometric sensingelement, a conductivity sensing element, a temperature sensing element,an oxidation-reduction potential sensing element, a chlorine sensingelement, an oxygen sensing element, an immunosensor, a DNA probe and anoptical sensor.

As illustrated in FIGS. 1D-1E, the sensors 111 can be formed in recesses116A. Any mechanism for forming the recesses 116A can be employed,including lithographic patterning and etching processes to producerecesses on the surface the substrate 116. The substrate 16alternatively can be formed as a first substrate 122 comprising aplurality of apertures 122A extending therethrough, and wherein eachsensor 111 is disposed on a surface of a second substrate 123, as shownin FIG. 1I. The second substrate 123 is bonded to the first substrate122 such that each sensor 111 faces a respective aperture 122A, of thefirst substrate 122, using for example a flip-chip process. Forming thesensors 111 in recesses 116A can be advantageous in embodimentsinvolving mechanisms for selective exposure of multiple sensors 111 asthis can protect the surfaces of the sensors 111; however, it is notnecessary to form the sensors in recesses in selective exposureembodiments.

As noted above, a mechanism for selectively exposing individual sensors111 to the fluid can be provided. For example, as illustrated in FIGS.1D, 1H and 1I, a cover membrane 120 (or multiple cover membranes, onefor each sensor 111) can be attached to a surface of a substrate 116,122, the cover membrane 120 covering the plurality of sensors 111, inthe recesses 116A, or below the apertures 122A. A plurality of heatingelements 121, for example, can be attached to the membrane 120 atpositions proximate to respective sensors 111. Each heating element 121can be selectively operable to generate an opening in the membrane 120thereby allowing a particular sensor 111 positioned proximate to arecess 116A or aperture 122A to be exposed to the fluid. As analternative to using heating elements 121 to selectively expose a sensor111, any suitable mechanisms which serve to dissolve the membrane orphysically remove or tear of at least a portion of the membrane 120 canbe used, such as shown in FIG. 1J by a conceptually illustratedmechanical perforator 124 or FIG. 1K by a conceptually illustratedmechanical gripper or scraper 125. The embodiments of FIGS. 1J and 1Killustrate in a generic way any number of mechanical means forselectively removing the membrane 120. In addition, any suitableactuation mechanism(s) can be used enable the mechanical perforator 124or the mechanical gripper or scraper 125 to be positioned adjacent to agiven sensor 111 and to selectively expose that sensor 111. For example,the sensors can be configured along a line or in a two-dimensional arrayon the substrate 116, and one or more actuators can be used to providerelative linear motion in one or two directions between the substrate116 and the mechanical member 125, 125. As another example, the sensors111 can be arranged along the circumference of a circle, and one or moreactuators can be used to provide relative rotational motion between thesubstrate 116 and the mechanical member 124, 125.

As with other embodiments disclosed herein, the substrate 116 can be asilicon substrate or can be another type of substrate such as, forexample, ceramic, glass, SiO₂, or plastic. An exemplary multi-sensorapparatus can also be fabricated using combinations of such substratessituated proximate to one another. For example, a silicon substratehaving some sensor components (e.g., sensing elements) can be mounted ona ceramic, SiO₂, glass, plastic or other type of substrate having othersensor components (e.g., other sensing elements and/or one or morereference electrodes). Conventional electronics processing techniquescan be used to fabricate and interconnect such composite devices. Eachsensor 111 can have one or more corresponding reference electrodes, thereference electrodes being located either on the same substrate as oneor more sensors 111 or on or more different substrates. For example,reference electrodes can be fabricated on one or more ceramic, SiO₂,glass, or plastic substrates (or other type of substrate), wherein asealed fluid reservoir is provided in the substrate for a givenreference electrode. Alternatively, multiple sensors 111 can share oneor more common reference electrodes, the common reference electrode(s)being located on the same substrate as a sensor 111 or on one or moredifferent substrates. Providing separate reference electrodes for eachsensor 111 can be beneficial since the performance of referenceelectrodes can degrade with use. By providing selective exposure ofreference electrodes associated with individual sensors 111, sensorperformance can be enhanced because fresh reference electrodes can beprovided when a new sensor is activated. A reference electrode can beexposed using the same exposure system as a sensor 111 or using adifferent exposure system.

The membrane 120 can be made of any suitable material such as a polymermaterial (e.g., polyester or polyimide) for instance and the membrane120 may be attached to the substrate 116, 122 via an adhesive or may beattached to the substrate 116, 122 by a heated lamination process. Thesensors 111 may be lithographically produced (e.g., using knownmicroelectronics processing techniques), dispensed or screen printed,for example, on a recessed or non-recessed surface of the substrate 116.

A multi-sensor apparatus can enable carrying out a confirmation functionas discussed above by allowing the processing unit 112A to selectivelyexpose a desired sensor in response to a measurement by another sensorindicative of a detection condition. The processing unit 112A cantrigger a power circuit to direct power to a heater 121 to expose thedesired sensor 111.

Another exemplary embodiment for selectively exposing sensors 111 isillustrated in FIG. 1L. As shown in FIG. 1L, a sensor unit 110′ isconnected to a fluid source via an input valve 115A and an output valve115B. The sensor unit 110′ comprises a housing member 119 with a wall119B to provide a sensor cavity 119′ and a fluid cavity 119″. Asubstrate 116 is provided on a backing plate 119A in the sensor cavity119′ adjacent to an aperture in the wall 119B to allow a sensor 111 tobe exposed to a fluid. A seal 119C, such as an o-ring, arranged adjacentto the aperture and positioned between a surface of the substrate 116and a surface of the wall 119B of the housing member 119, to seal thesubstrate 116 against the housing wall 119B. An actuator 119D moves thebacking plate 119A and the substrate 116 to selectively locate anindividual sensor 111 to a region of the aperture such that theparticular sensor 111 is exposed to the fluid. The substrate 116 ispreferably flat to allow for a good seal, but the invention is not solimited. As discussed previously, sensors 111 can be formed on arecessed or non-recessed surface of the substrate 116. To minimize thepotential for fluid leakage into the sensor cavity 119′, the valves 115Aand 115B can be actuated to partially or substantially drain the fluidcavity 119″ before selectively exposing a new sensor 111 with theactuator 119D.

The sensors 111 can be lithographically produced, deposited or screenprinted on a recessed or non-recessed surface of the substrate 116, andmight be formed at the circumference of a circle so as to allow theactuator 119D to be a simple carousel mechanism using rotational motionas shown in FIG. 1M, or can be formed in a staggered or straight line asshown in FIG. 1N, or in a two-dimensional array, for instance, and theactuator 119D can provide for a linear motion in one or more dimensions.The substrate can be in the form of substrate 116 with recesses 116A asshown in FIGS. 1N and 1E, or can be in the form of the flip-chip bondedsubstrate 122, 123 shown in FIG. 1F.

In view of the above, it will be apparent that carousel or linear motionembodiments can be used in conjunction with sensors 111 covered by atleast one membrane 120 attached to a surface of the substrate 116 (e.g.,FIGS. 1J and 1K), in which case a mechanical member 124, 125 selectivelydisplaces or perforates the at least one membrane 120 in a regionproximate to an individual sensor 111 to allow the particular sensor 111to be exposed to a fluid. In this regard, a configuration similar tothat illustrated in FIGS. 1L and 1M (or 1N) can be used. The actuator119D can provide relative motion between the substrate 116 (mounted onbacking plate 119A) and the mechanical member 124, 125 to allow themechanical member 124, 125 to selectively displace the at least onemembrane 120. The seal 119C and housing 119 may not be necessary inembodiments involving a membrane 120.

In the embodiments in which motion of the sensors 111 is designed tooccur, electrical connections 126 could be configured to align with acontact pad 127 or pads to assure electrical connection between thesensors components 111, 113 and the processor 112A.

Distribution of Sensor Elements

Unlike some prior systems which required the regional water authority toinstall water quality measuring devices at various points within thewater treatment plants and/or within a water distribution network, thepresent inventors have devised a mechanism wherein the distribution ofsensor units can utilize pre-existing commercial distribution systems224, such as illustrated in the exemplary embodiment shown in FIG. 2.For instance, a sensor unit supplier 225 (e.g., an original equipmentmanufacturer, reseller or wholesaler) can supply or arrange to havesupplied sensor units 110 to pre-existing product distributors 226,which might include among others water treatment services 226A, such asCulligan Water Treatment Services, Ecco Water Systems, MIlliporeCorporation, and GE Specialty Materials, for example. These watertreatment services 226A provide equipment and/or consumable supplies fortreating water such as softening agents, filtration devices, filters,etc. to residential locations (e.g., houses, apartments, mobile homes,etc.) 227A, businesses 227B, industrial plants 227C and/or governmentfacilities 227D. The water treatment services 226A provide sales,distribution and installation of the sensor units 110 throughpreexisting commercial distribution systems 224, thereby minimizing thecost of establishing supply chains of sensor units 110 to end users 227at residential locations 227A, businesses 227B, industrial plants 227Cand government facilities 227D, for example, or any location that wouldwant or use the services of a water treatment service 226A, for example.Alternatively or additionally, the government regional water authoritycan be utilized as an installer of sensor units at the water authority'sexisting sensor locations and/or additional locations, and/or can alsobe utilized as a distributor of sensor units to homes, businesses,industrial plants, and government facilities, wherein monitoring of thesensor units can be carried out by another entity other than theregional water authority.

For instance, water treatment services 226A can receive sensor units 110from a sensor unit supplier 225 for installation at the sites of the endusers 227. The water treatment service 226A can sell the sensor units110 as an added value to their overall water treatment service, asexplained in more detail with reference to FIG. 3, below. Watertreatment services 226A thereby act as sales and distribution networksfor the installation of sensor units 110 at the end users 227.Additionally, because water treatment services 226A often install theequipment they are selling, leasing or otherwise conveying to the enduser 227, this installation can include installation of the sensor units110, and can further include establishing communication between thesensor units 110 and centralized data collection points such as thewater treatment service 226A, smart nodes 332 and/or a singlecentralized data collection point 333 within a water monitoring networkof a geographic or political region or regions, as explained withreference to FIG. 3, below. The water treatment service 226A can thuscarry out on-line monitoring of intake water and treated (e.g.,filtered) water and, as mentioned previously, can also utilize suchmonitoring to guarantee or certify the quality of treated water atend-user delivery points 227A-227D.

Alternatively, the sensor unit supplier 225 can supply sensor units 10or cause them to be supplied directly to the retail outlets 226B (e.g.,retail outlets in physical buildings or retail outlets provided throughInternet websites, or both) or through wholesale outlets to retailoutlets 226B. The end users 227 would then obtain sensor units 110directly from retail outlets 226B for self-installation or end-userassisted installation. Hence, the retail outlet 226B provides the salesand distribution mechanism, whereas the end user 227 providesinstallation of the sensor units 110 at points of end use of the waterin the water distribution system. The end user 227 would then establishor facilitate establishment of communication with a monitoring network330. In some instances, the sensor unit 110 can include a cellularcommunication device with its own unique identification code. The enduser 227 can simply turn on the cellular communication device and eitherenter the end user's location or address, or allow the cellularcommunication device to be located through triangulation if thatcapability exists within a particular cellular system. Of course, thismechanism could be employed regardless of how the sensor unit 110 wasdistributed.

Another form of preexisting commercial distribution system 224 includesregional water authorities 226C which, in the regular course of theiractivities, installs water meters and the like at the locations of endusers 227, whether residential 227A, businesses 227B, industrial plants227C or government facilities 227D. The sensor units 110 would simply beinstalled by the regional or multi-regional water authority 226C or itscontractors. In this circumstance, there may not be an actual sale orother conveyance of the sensor unit 110 to the end user, who may noteven be aware of the installation. Meter manufacturers can incorporatesensor unit capabilities into standard meters for selective activationby the regional water authority 226C, by the meter manufactures oranother entity interested in providing data from end-point locationswithin a water distribution system. Here it can be seen that theinvention can be used in conjunction with other fluids, such as naturalgas, if there is a need or a need develops.

Additionally or alternatively, home security, home (e.g., utility)monitoring, and health monitoring services 226D can provide sales,distribution and installation of sensor units 110 as part of or as valueadded to the offered monitoring services. For instance, home securityand health monitoring services 226D, as well as generalized homemonitoring services which may include monitoring the usage of utilities,can add water quality monitoring capabilities as part of their services.The sales, distribution and installation of sensor units 110 would thenuse the same network these services have established to sell, distributeand install other equipment to perform other home and health monitoringfunctions.

As should be appreciated by the above, the sensor unit distributionsystem 224 for distributing sensor elements 110 utilizes one or morepre-existing commercial distribution systems 226 to sell, distribute andinstall sensor units 110 at the location of the end user 227. Virtuallyany product distribution system reaching residences 227A, businesses227B, industrial plants 227C and/or government facilities 227D (or anylocations where water is used by end users in a water distributionsystem) can be used to also distribute sensor units 110, perhaps asadded value services or products. The thus distributed sensor units 110can form a water monitoring network 330 specific to the particularpre-existing product distribution system 226, or sensor units 110distributed by a variety of pre-existing product distribution systems226 form a larger water monitoring network 330, or a mixture whereincertain data gathered by sensor units 110 distributed by a particularpre-existing product distribution system 226 would be proprietary to theparticular pre-existing product or service distributor 226 (e.g., datarelated to water treatment equipment performance), but other data (e.g.,data related to water quality within a water distribution system) wouldbe provided to a water quality monitoring network 330. In this way, alarger and perhaps more distributed panel of sensor units 110 can bedistributed and installed at relatively little cost to the waterauthorities, for instance.

With reference to FIG. 3, various aspects of the present disclosureincluding data collection, centralized or distributed data analysis anddata distribution will be explained by way of an exemplary watermonitoring system 330. In the exemplary water monitoring system 330,various sensor units 110A-110F at sites A-F are connected to the waterquality monitoring system 330 by communication links as identified abovewith reference to the details of the sensor units 110. While six sensorunits 110A-110F are shown in FIG. 3, many more are contemplated and thedrawings should not be relied upon for judging orders of magnitude orthe number of sensor units 110, smart nodes 332 or centralized datacollection points 333.

The sensor units 110A-110C, for instance, are connected to a smart node332A (a node that has data processing power), whereas other sensor units110D-110F may be connected to a separate smart node 332B or the samesmart node 332A as warranted by various factors involving the networkand water authorities, including the bandwidth of communication devices,the appropriateness of distributing processing an analysis of data, etc.The smart nodes 332 can have a relationship to the region or authorityof regional water authorities 226C, for example.

The sensor units 110 may provide raw data, or just confirmed detectionevents to smart nodes 332 and/or directly to a centralized datacollection point 333. The double-sided arrow lines in FIG. 3 indicatethe flow of data up the hierarchical network 330, and data and inquiriesdown the hierarchical network 330, there being contemplated two-waycommunication in some embodiments. In certain embodiments, onlycommunication going up the hierarchical chain is necessary.

The smart nodes 332 may process the raw data to monitor, identify andconfirm detectable events in the water quality. Alternatively, thesensor units 110 can provide monitoring, identifying, confirming andreporting functions to the smart nodes 332 or centralized datacollection points 333. Whether the smart nodes 332 process raw data orrely upon the sensor units 110 for confirmed data, the smart nodes 332having received data from a variety of sensor units 110A-110F at avariety of sites 110A-110F can aggregate and further process such datato determine historical water quality measures, overall qualitymeasures, trends and multipoint measures of a regional waterdistribution pipe system. The introduction point or source of possiblecontaminants, water main breaks, freezing pipes, etc., can be traced byanalysis of the multipoint data gathered at smart nodes 332 orcentralized data collection points 333 by mapping techniques based onthe locations of the sensor units 110 within a water distribution systemand the measure and/or reported events from the distributed sensor units110.

The data collection can run in real time, and can continuously, orintermittently (e.g., periodically at pre-set time intervals) monitorfluid quality, or upon inquiry, or operate based on stored data at thesensor sites 110A-110F, depending on the data storage and communicationcapabilities of the sensor units 110. Real-time data has obviousadvantages and it should be noted that most types of sensor units 110contemplated above measure in real time (whether continuously,periodically or upon inquiry), rather that taking samples and testingthe samples at a later time.

Additionally, the smart nodes 332 may periodically or at the command ofan operator inquire as to measured data from the sensor units 110 ascommunication protocols or information needs might dictate. Thecentralized data collection as represented by the smart nodes 332 andthe centralized data collection point 333 can be conducted over privateor public networks (e.g., VPN, WAN, the World Wide Web including theInternet), dedicated telephone lines, cellular networks, or virtuallyany other form of communication. For instance, telephone land-lines andtelephone wireless networks can be utilized for a call-up by the sensorunits 110 for periodic interrogation by the smart nodes 332 orcentralized data collection point 333 of the sensor units 110.Additionally, other communication protocols can be used includingcommunications over a pre-existing power grid by a super-imposed carrierover a power line using known or future protocols and techniques.Further, acoustic waves carried by water in the water distributionsystem can be utilized for information transmissions. Othercommunication mechanisms can be utilized independently or incombination, including fiber optics, satellite communications andvirtually any communication protocol or mechanism capable oftransmitting raw and/or analyzed data between the sensor units 110 andthe smart nodes 332 and/or centralized data collection points 333.

Additionally and/or alternatively, the sensor units 110D-10F cancommunicate to smart nodes 332 and/or centralized data collection points333 through other entities such as water treatment services 226A, homemonitoring (security and utility) services and/or health monitoringservices 226D, retail outlets 226B, and/or regional water authorities226C, which would then convey data to smart nodes 332B, as illustratedin the exemplary embodiment shown in FIG. 3.

With respect to data distribution, once the data has been gathered andanalyzed, raw data, analyzed data and aggregated data can bedistributed, whether from smart nodes 332 that may be regional and/orthat may be specific to regional water authorities, or to centralizeddata collection points 333 that may be multi-regional in nature. Thetypes of data can be categorized as data containing user identifiableinformation and aggregated data, which may or may not contain useridentifiable information.

Data containing user identifiable information is useful for end users227 for a variety of reasons. For instance, for sensor units 110 thatinclude a sensor 111 or sensor element(s) 113 or sensor groupspositioned after a water treatment device such as a water softener orfilter 114, data relating to a parameter indicating a water qualitydetection event can be utilized by the end user 227 to inform him or herthat filters and/or water treatment chemicals need to be replaced orreplenished as the situation dictates. This can be done at the sensorunit 110 by indicators or the like, or through communications from smartnodes 332 or centralized data collection points 333. The end user 227may also be interested in the performance of the local regional waterauthority 333C to serve as a check upon the performance of the regionalwater authority 226C insofar as the end user 227 may question theregional water authority 226C when the water quality has been reduced orchanged.

Raw and analyzed data from the smart nodes 332 can be provided toregional water authorities 226C for determining compliance with waterquality standards and as internal checks on the performance of theregional water authority 226C. Additionally, raw and analyzed data fromsmart nodes 332 and/or centralized data collection points 333 can besupplied to multi-regional water authorities 335 such as national waterauthorities to determine compliance with appropriate water qualitystandards by regional water authorities 226C and as determinations ofthe overall health of the multi-regional water supply to detect thepresence, persistence and extent of contaminants in the multi-regionalwater supply so as to determine or trace the origin and extent ofproblems within the water supply. Additionally, the information can besupplied back to preexisting commercial distribution systems 224.

For instance, water treatment services 226A might be interested indetermining the water quality of water leaving water treatment devicesinstalled at the location of end users 227 and may be interested in thewater quality of the water entering the water treatment devices, so asto alert end users 227 of the need for replenishing chemical suppliesand/or replacing filters, or automatically providing the end user 227with such supplies, or to alert the end user 227 of problems with thewater supply, particularly those not correctable by the water treatmentdevices, as the terms of any agreement between the water treatmentservice 226A and the end user 227 may dictate. Such alerts can beprovided in a variety of ways, such as, using local indicator (e.g., alight, audible alarm, or other form of alert on the sensor unithousing), displaying information on a display (e.g., a display locatedon the sensor unit housing), making a telephone call to the end user, orsending an electronic message (e.g., e-mail, pager message, SMS, etc.)to the end user, or any combination of these approaches. Moreover, ifpotentially dangerous water quality conditions are detected, an alertcan also be sent to the regional water authority. For example, if anidentification event (e.g., relating to a potentially dangerouscondition) is detected through comparison of sensor data with a databaseof potential chemical profiles, a corresponding alert can be sent toboth the end user and the regional water authority. Also, depending uponthe condition identified, a suitable control valve(s) can be operated toshut off the water supply to the end user as discussed previously.

Further, where water treatment devices (e.g., filters) are distributedto be associated with sensor units, water treatment services canguarantee or certify the quality of water treated by the water treatmentdevices as an additional service to end users. Moreover, customers canbe billed per unit of water treated by the water treatment devices,either in place or, or in addition to, being billed for the watertreatment devices and/or consumables themselves.

With respect to retail outlets 226B, the retail outlet 226B can use thedata to prompt end users 227 to purchase additional filters and/orchemicals and/or replace filtration and treatment devices based on ameasure of the water quality either entering and/or exiting suchdevices.

The raw and analyzed data can also be provided to home monitoring andhealth monitoring services 226D for the benefit of informing the endusers 227 as to the quality of the water entering the domain of the enduser 227.

In addition to the foregoing entities 226A-226D, 335 that might beinterested in the quality of water at the location of the end user 227,other entities may be interested in the quality of water reaching endusers 110. For instance, water quality watch groups may be interested inaggregated data to determine trends in the water quality to rate andimpose pressure on regional and multi-regional water authorities 226C,335. Government entities may be interested in determining the viabilityof the water distribution infrastructure both on a regional andmulti-regional scale. Academics may be interested in the data todetermine global trends in water quality. Real estate sales facilitatorsmay be interested in identifying water quality as one factor among manyfactors that might be used in a home owner's decision to buy or sell anindividual house within a particular region. Government agencies such asthe U.S. Center for Disease Control, Evironmental Protection Agency,Department of Homeland Security, and hospitals may be interested in thedata to alert the public and/or determine the origin and spread ofdisease, toxins or other issues of health having origins in the watersupply that might concern a community or a nation. Aggregated data canbe used to determine trends, and/or user identifiable data may be usedto pinpoint particular sources of problems in regional waterdistribution networks or multi-regional water distribution networks. Theunderlying theme is that the water monitoring system provides amechanism wherein various types of information concerning water qualitycan be shared and/or sold to a variety of interested parties onexclusive or non-exclusive bases by a party that can be relativelyneutral and independent.

Consideration for End Users and for Access to Data

Insofar as end users 227 are asked to install or permit the installationof sensor units 110 capable of communicating data outside the domain ofthe end users 227, some consideration to the end user 227 would seemappropriate in some circumstances. For instance, the end user 227 mayview as consideration the ability of the sensor unit 110 and/or waterquality monitoring system 330 of which his or her sensor unit 110 ispart to alert him of potential hazards that may not otherwise beavailable. For instance, to obtain the function of having a localindicator provide information about water quality, the end user 227might have to agree to share information with a water quality monitoringsystem 330. Alternatively or additionally, the end user 227 might agreeto obtain the benefit of analysis that are not detectable via theprocessing power of a individual sensor unit 110 at a price point theend user 227 is willing to pay. Hence, the consideration for thecommunication of data to a water quality monitoring system 330 would bethe value added to sensor units 110 a price point that the end user 227is willing to pay.

Additionally, the end user 227 would likely be aware or be made awarethat the communicated information is to the benefit of the overallcommunity. It would appear that the end user 227 would have a smallthreshold in the way of privacy concerns insofar as the volume of wateruse is already monitored at the end user location and the end user 227imparts no private or personal information upon the quality of the waterand therefore the information developed by the sensor units 110.

Additionally or alternatively, the sale or other conveyance of thesensor unit 110 can be conditioned upon the agreement by the end user227 for the transmission of data to smart nodes 332 or centralized datacollection points 333. Further, sale of the equipment, subscription ofmonitoring or water treatment services 226A and other subscription basedservices can provide consideration to the end user 110 as well aslend/lease, can be condition upon providing the communication link andthe data provided by the sensor units 110.

Additionally, water authorities 226C can require the installation ofsensor units 110 as part of services such as the supply of water orother services generally provided by local governments. Finally, thesensor units 110 may be required to be installed by the end user 227 orbe permitted by the end user 227 to be installed by regulation ofgovernment.

As consideration for access to both raw and analyzed data, those wishingto access the data can do so by subscription base payments either of aperiodic nature (e.g., monthly and/or yearly payments), fully paid-uplicenses, fees or per individual reports or a combination thereof.Additionally, fees could be based upon the report of any particulardetected event or based on the number of detected events per report.Aggregated data reports can add value by providing historical data,comparison data or other added value imparted by the intelligence anddata bases of the reporter service or entity, such that the raw data,the individually end user identifiable data, and the aggregated data canbe analyzed by informed individuals and/or through algorithms to provideenhanced value to the quality of the data being reported. Compensationcan take the form of payments by entities capable of assisting the enduser 227 as part of consideration for any such referral oridentification of prospective end users 110 in need of assistance.

As can be seen, the present disclosure has been explained by way ofexemplary embodiments which it is not limited. Various modifications andalterations of the core concepts will occur to those skilled in the artwithout departing from the scope of the invention as articulated in theclaims appended hereto. It is reiterated that advantages and attendantaspects of various embodiments of the invention are not necessarily partof the invention. Rather, the invention should be determined by a reviewof the claims appended hereto, as well as equivalents of the elementsthereof.

1. A multi-sensor apparatus for monitoring a fluid, comprising: aplurality of sensors, each sensor being configured to be exposed to afluid; at least one cover membrane that covers the plurality of sensors;and a plurality of heating elements attached to the at least one covermembrane, a given heating element being positioned proximate to a givensensor, wherein each heating element is selectively operable to generatean opening in the at least one membrane, thereby allowing a particularsensor positioned proximate to the opening to be exposed to the fluid.2. The multi-sensor apparatus of claim 1, wherein said fluid is water.3. The multi-sensor apparatus of claim 1, further comprising multiplesubstrates, the plurality of sensors being attached to the multiplesubstrates.
 4. The multi-sensor apparatus of claim 1, further comprisinga substrate, wherein the plurality of sensors are supported by thesubstrate, and wherein the at least one membrane is attached to asurface of the substrate.
 5. The multi-sensor apparatus of claim 4,wherein at least one of said sensors comprises a plurality of seansingelements.
 6. The multi-sensor apparatus of claim 4, wherein at least oneof said sensors comprises at least one of an ion-selective sensingelement, an amperomertric sensing element, a potentiometric sensingelement, a conductivity sensing element, a temperature sensing element,an oxidation-reduction potential sensing element, a chlorine sensingelement, an oxygen sensing element, an immunosensor, a DNA probe and anoptical sensor.
 7. The multi-sensor apparatus of claim 4, wherein thesensors are recessed from a surface of the substrate.
 8. Themulti-sensor apparatus of claim 4, wherein the membrane comprises apolymer material.
 9. The multi-sensor apparatus of claim 8, wherein thepolymer material comprises polyester or polyimide.
 10. The multi-sensorapparatus of claim 4, wherein the membrane is attached to the substratevia an adhesive.
 11. The multi-sensor apparatus of claim 4, wherein themembrane is attached to the substrate by a heated lamination process.12. The multi-sensor apparatus of claim 4, wherein the plurality ofsensors are lithographically produced on a recessed surface thesubstrate.
 13. The multi-sensor apparatus of claim 4, wherein saidsubstrate comprises a first substrate comprising a plurality ofapertures extending therethrough, and wherein each sensor is disposed ona surface of one of multiple separate substrates, each separatesubstrate being bonded to the first substrate such that each sensorfaces a respective aperture of the first substrate.
 14. The multi-sensorapparatus of claim 13, wherein the separate substrates are bonded to thefirst substrate using a flip-chip process.
 15. A multi-sensor apparatusfor monitoring a fluid, comprising: a plurality of sensors, each sensorbeing configured to be exposed to a fluid; at least one membraneattached to a surface of a substrate, the at least one membrane coveringthe plurality of sensors; and a mechanical member for selectivelydisplacing the at least one membrane in a region proximate to aparticular sensor to allow the particular sensor to be exposed to thefluid; and an actuator for providing relative motion between thesubstrate and the mechanical member to allow the mechanical member toselectively displace the at least one membrane.
 16. The multi-sensorapparatus of claim 15, wherein said fluid is water.
 17. The multi-sensorapparatus of claim 15, wherein at least one of said sensors comprises aplurality of sensing elements.
 18. The multi-sensor apparatus of claim15, wherein at least one of said sensors comprises at least one of anion-selective sensing element, an amperometric sensing element, apotentiometric sensing element, a conductivity sensing element, atemperature sensing element, an oxidation-reduction potential sensingelement, a chlorine sensing element, an oxygen sensing element, animmunosensor, a DNA probe and an optical sensor.
 19. The multi-sensorapparatus of claim 15, wherein the sensors are recessed from a surfaceof the substrate.
 20. The multi-sensor apparatus of claim 15, whereinthe at least one membrane comprises a polymer material.
 21. Themulti-sensor apparatus of claim 20, wherein the polymer materialcomprises polyester or polyimide.
 22. The multi-sensor apparatus ofclaim 15, wherein the at least one membrane is attached to the substratevia an adhesive.
 23. The multi-sensor apparatus of claim 15, wherein theat least one membrane is attached to the substrate by a heatedlamination process.
 24. The multi-sensor apparatus of claim 15, whereinthe plurality of sensors are lithographically produced on a recessedsurface the substrate.
 25. The multi-sensor apparatus of claim 15,wherein said substrate comprises a first substrate comprising aplurality of apertures extending therethrough, and wherein each sensoris disposed on a surface of one of multiple separate substrates, eachseparate substrate being bonded to the first substrate such that eachsensor faces a respective aperture of the first substrate.
 26. Themulti-sensor apparatus of claim 25, wherein the separate substrates arebonded to the first substrate using a flip-chip process.
 27. Themulti-sensor apparatus of claim 15, wherein the mechanical memberperforates the at least one membrane.
 28. The multi-sensor apparatus ofclaim 15, wherein the mechanical member mechanically removes the atleast one membrane.